I was making a batch of mousseline this weekend, and I thought I’d report my results making it over a two-day period.
On Saturday, I did the “sugar-egg white” part. This was a fairly sizeable batch - 485g whites, which required 3.25 lbs butter. I covered the whipped/sugared whites and fridged it overnight.
On Sunday, I noticed the whites had shrunk some.
I took the whites and butter out of the fridge around 12:15 so they’d have 3 hours to come to room temp. They were around 68 degrees when I was ready to work with them.
I was unflavored with a little over 1/2 the batch and strawberry with the other half, so I whipped half of the butter and started dishing-up half of the whites (by weight).
As I was dishing, I noticed that there was a pool of liquid at the bottom of the whites—looked like between 1 and 2 cups! So I dished the whites back in and mixed them with the liquid. They were hte consistency of melted ice cream now, rather than “froofy”.
However, I pitched half of it into my butter and, in true mousseline fashion, mixed—slight expected curdle followed by a nice, creamy, stiff mousseline. Packed up that half, and made the rest, adding about 3 oz. of powdered, freeze-dried strawberries mixed with a little water ot make a thick paste. Super-fruity and fresh.
So, in case you ever want to make mousseline, but don’t have time to do it all with the cooling and what-not, you can make it over two days without stressing about the whites sort of weeping overnight.
p.s. I took 1 c. of the plain and added a substantial amount of matcha powder for a nice dark green. I am doing an experiment to see if the intense grass flavor is as elusive as it is said to be. In fact, I hope it generally goes away to leave me with a (more or less) ‘plain,’ but green, mousseline.